1. Field of the Invention
This invention relates to data recording apparatus and more particularly to apparatus that records data in a prescribed spatial arrangement that corresponds to the spatial arrangement of material the characteristics of which the recorded data represents.
2. Description of the Prior Art
There are many known forms of fraction collectors which are useful in determining the presence and quantity of a given substance in a test solution. In utilizing such prior art fraction collectors, the unknown substance is passed through a fractionating column, and the output of the column is collected in a series of individual containers in timed sequence. The sequence in which the constituents or fractions of the material exit the fractionating column is a function of the retention properties of each particular constituent. Although such unknown materials can often be divided into a large plurality of individual fractions, it is typical that but a few of the individual fractions require further attention or analysis. In order to identify the particularly pertinent fractions, it is conventional to record one or more particular characteristics (e.g., optical density, electrical conductivity, ph, radioactivity and the like) of the material exiting the fractionating column and then determining from the recorded data which particular fractions are of greatest pertinence. Prior art techniques for recording such data have taken the form of a strip chart recorder where a graph is drawn as the strip advanced at a prescribed rate. Although the data recorded is accurate, its use is difficult because extra steps are required in coordinating and identifying a particular fraction with a particular point on the graph. The present invention, by way of contrast, records data in a spatial arrangement that corresponds with the spatial arrangement of the collected fractions so that the particular fractions of most interest can be readily identified by visual inspection and comparison between a chart achieved according to the invention and the fractions collected from the column.
One specific prior art fraction collector is disclosed in U.S. Pat. No. 3,871,426 (Class 141/130). In the patented fraction collector a plurality of fraction collecting containers are arranged in a spiral path in a disc. The present invention is particularly suitable in conjunction with the fraction collector disclosed in U.S. Pat. No. 3,871,426 because the time base is linear and independent of the radius of the spiral at any point.